i built one a using scavenged recessed ceiling light kit from the job site. i just happened to luck out that it had a ballast which was for 26 watt compact fluorescent and it could be wired for 1 or 2 bulbs. i'm planning on putting 52 watts over a 10 or 15 gallon for growing some high light plants and making it my shrimp tank. i found the bulbs at lowes or hd (cant remember which) they were made by Lights of America and are 6500k and cost only $10. I'm still working on constructing the hood out of some aluminum stock left over from work.
if you can find an electric supplies store near you, your ballast options would be much better than HD or Lowes.